Gouging electrode rods heretofore used are formed by sintering carbon to provide a length of rod and plating the rod surface with copper or flame-spraying the rod surface with aluminum. Since such electrode rods are limited in length, continuous gouging operation requires frequent exchange and hence the efficiency is low. Further, shortened electrode rods account for a loss of about 15%. On the other hand, various types of connectable carbon electrode rods have been proposed, but they have drawbacks that connection takes time and that the gouged groove configuration varies at the connection.
Thus, various types of wirelike electrode rods intended to elminate these drawbacks have been devised.
Among the conventional gouging wires, a typical one is in the form of a filler section serving as an electrode material wrapped in a shell which is a hoop of metal such as iron or stainless steel. As for the composition of said filler section, usually it consists mainly of carbon with suitable amounts of binder and stabilizing agent added thereto.
This type of gouging wire electrode, as compared with the aforesaid gouging carbon electrode rod, has the following drawbacks.
(1) The stability of arcs during discharge is poor. That is, since arcs can hardly be produced continuously, it is impossible to obtain a uniform gouged groove.
(2) Since the rod is consumed so rapidly that it can hardly be treated by hand, requiring an automatic machine. Further, it is comparatively high in cost.